RECTANGULAR SECONDARY BATTERY

摘要

[Problem] To stably form a large welding trace (nugget), which is formed inside a positive electrode core exposed part or a negative electrode core exposed part of a rectangular secondary battery, on the collector side. [Solution] A rectangular secondary battery is provided with a negative electrode collector (18) or positive electrode collector, which is disposed on either one of a wound negative electrode core exposed part (15) and a positive electrode core exposed part, and a negative electrode receiving member (19) or positive electrode receiving member, which is disposed on another surface. In a region in which either the negative electrode collector (18) or the positive electrode collector faces the negative core exposed part (19) or the positive core exposed part, a recessed part (30) is formed in part of the surface of the side not facing the negative electrode core exposed part (19) or positive electrode core exposed part, and the thickness of this recessed part (30) is formed so as to be thinner than the thickness of the other parts. Resistance welding is carried out in this recessed part.